Electrical power networks used in recent years have a network structure that have multiple electrical power supply sources, such as electrical power companies and homes equipped with a photovoltaic power generation facility; therefore, it is difficult to manage the supply and demand of electrical power. Consequently, network structures have been developed to efficiently control the electrical power networks and to increase the efficiency of electrical power usage over the entirety of each electrical power network.
For example, there is a technology that controls the electrical power supply and demand for each area in an electrical power network. FIG. 26 is a schematic diagram illustrating an example of an electrical power network. As illustrated in FIG. 26, with this technology, an electrical power network A1 is divided into multiple areas A2 called areas and multiple areas A3 called zones. Furthermore, with the technology that controls the electrical power supply and demand, a smart meter is installed in each home in a zone. This first smart meter transmits, regularly to another smart meter in the same zone to which the first smart meter belongs, information related to an electrical power balance including both the available amount of electrical power supply at this point and the amount of electrical power consumption. Furthermore, when receiving information related to an electrical power balance from another smart meter, the first smart meter transmits a reply based on the information related to its own electrical power balance. In this way, the technology that controls the electrical power supply and demand performs a matching of electrical power supply and demand in a zone, thereby controlling the electrical power supply and demand in the zone.
Furthermore, with the technology that controls electrical power supply and demand, as illustrated in FIG. 26, an area broker D1 that manages the electrical power supply and demand in an area is installed in each area. The area broker D1 recognizes, based on information related to the supply and demand balance of the electrical power aggregated in each zone, an excess or deficiency of electrical power related to each zone in an area. Then, by determining the adjustment of electrical power between the zones, the area broker D1 controls the electrical power supply and demand in an area.
Furthermore, as a technology related to controlling electrical power supply and demand, there is a technology that performs, by using an electrical power storage station, energy management including supply and demand adjustment in a short time, supply and demand adjustment in accordance with a time zone, such as in the daytime or in the evening, and supply and demand adjustment in accordance with the weather, such as when the weather is fair or it is raining.
Non-Patent Document 1: Sho Shimizu, et al., “A study on power optimization with inter-zone optimization and inter-area optimization”, Mar. 16, 2010 The Institute of Electronics, Information and Communication Engineers (IEICE) General Conference, Mar. 16, 2010
Non-Patent Document 2: Masahide Yamaguchi, GS Yuasa Power Supply, Ltd., “battery technology in the new energy field”, March 14
However, with the technology disclosed in the Non-Patent Document 1, a zone is optimized by performing an instant matching in a locality (electrical power is immediately supplied between homes), which is a basic method. Consequently, with the technology disclosed in the Non-Patent Document 1, it is difficult to optimize any large imbalance of the electrical power supply and demand in a zone or to optimize the variation in electrical power usage in the time axis direction. For example, if the electrical power usage in a home exceeds the amount of electrical power supply, it is difficult to immediately detect the insufficiency of electrical power and promptly supply electrical power. Furthermore, an electrical power generating device, such as a photovoltaic power generator, installed in a home transmits electrical power by using a low-voltage direct current power supply. When sending electrical power by using a low-voltage direct current power supply, the loss of electrical power during transmission increases in proportion to the distance. However, with the above-described technology that controls the electrical power supply and demand, when electrical power is transmitted, the location relationship between the side that supplies electrical power and the side that receives the supply of the electrical power is not considered. Consequently, there is a problem in that the side that can supply electrical power does not immediately detect the insufficiency of electrical power on the side that receives the supply of the electrical power, and furthermore, the loss of electrical power when the electrical power is transmitted becomes large. Furthermore, with the technology using the above-described electrical power storage station, when performing energy management, such as the supply and demand adjustment, the location relationship between the side that supplies electrical power and the side that receives the supply of the electrical power is not considered; therefore, a delay may occurs until the electrical power is transmitted and a loss of electrical power when the electrical power is transmitted may occur.
Furthermore, if an electrical power storage station is accommodated in an electrical power network, the loss of electrical power may sometimes be low if electrical power is supplied from the electrical power storage station. However, because the above-described technology that controls the electrical power supply and demand is considered based on the assumption that electrical power is demanded and supplied between homes, even if the electrical power storage station is accommodated in the electrical power network, the loss of electrical power when electrical power is transmitted is inevitable.